Analysis Of The Static And Dynamic Performance Of Suspension Bridge With CFRP Cables

From several meter, tens of meters of stone plank bridges, to kilometer level long-span bridges, each time the bridge span has the big leap all to accompanying by the appearance of new material. With the rapid development of transportation enterprise, the humanity needs to push the suspension bridge to a greater span to satisfy the demand of spanning channel. Because of the weak corrosion resistance and the heavy weight of traditional steel, the steel cables system is not suitable for the longer suspension bridge in the future. While the new material-Carbon Fiber Reinforced polymer (CFRP) with high strength, low density and excellent corrosion resistance properties, shows more advantage in the construction of long-span bridges. Up to date, since no report on the realization of suspension bridge with CFRP cables could be found, only the basic theory research on the static and dynamic performance and the influence parameter of suspension bridges with CFRP cable or steel cable are studied contrastively here.The calculation theories of suspension bridges, including elastic theory and deflection theory in early-stage, finite displacement theory and analytic calculation theory used presently are introduced systematically. Moreover, the merits and faults of the latter two methods are compared and analyzed, which provides theoretical basis for the analysis of static and dynamic characteristic of suspension bridges.The static performance of the suspension bridge with CFRP cables and steel cables under vehicular load, still wind load and temperature is analyzed making use of the finite-element method. The condition of half-range and full-load of the two types of bridges is analyzed contrastively. It indicates that the discrepancy of internal force of the both is small and the displacement of CFRP cable is little larger than steel cable, but still can satisfy the request of design standard through the analysis of displacement and internal force responses of the main cable, suspender and stiff girder;The function effects of heating-up and cooling on the both are analyzed contrastively and it indicates that the temperature effect of CFRP cable suspension bridge is much smaller than that of steel cable suspension bridge.The dynamic characteristics of CFRP cable suspension bridge is studied preliminarily which provides gist for the wind-induced vibration, seismic and other studies in further research. Through establishing the three-dimensional model of CFRP cable suspension bridge, the characteristics of natural vibration of the two kind of cable suspension bridges are analyzed contrastively and the influences of rise-span ratio, the central buckle, the rigidity of main cable, stiff girder , suspender and other parameters on the dynamic characteristics of the CFRP cable suspension bridge are also analyzed.